Reactive voltage control method and apparatus, medium, and computing apparatus

Abstract

This disclosure provides a reactive power voltage control method, apparatus, medium, and computing device. The reactive power voltage control method includes: calculating the system impedance assessment value of the grid connection point at the current moment based on the electrical information of the grid connection point; determining the current system impedance value based on the system impedance assessment value; determining the proportional coefficient and integral coefficient of a proportional-integral (PI) algorithm based on the current system impedance value; and performing reactive power voltage control at the grid connection point using a PI algorithm based on the determined proportional and integral coefficients. The reactive power voltage control method according to embodiments of the present invention can quickly and accurately control reactive power voltage.

Description

Technical Field

[0001] This invention generally relates to the field of new energy, and more specifically, to a reactive voltage control method and apparatus, a medium, and a computing device. Background Technology

[0002] In the entire energy system, with the continuous increase in the proportion of new energy sources and the continuous increase in the capacity of single units, the installed capacity of power plants is also reaching new highs.

[0003] Furthermore, areas where renewable energy is connected to the grid often lack local loads and conventional power sources. The electricity generated by renewable energy power plants needs to be transmitted over long distances to load centers, resulting in significant reactive power and voltage fluctuations in the power transmission channels as renewable energy output changes. Therefore, increasingly stringent requirements are being placed on reactive power control and voltage stability at renewable energy power plants.

[0004] In my country, a three-level dispatch control method has been adopted to achieve voltage control of the entire network. The reactive power voltage control of new energy power plants is the first level of control. The overall control requirements need to meet the requirements of fast control response speed and high accuracy, which plays an extremely important role in the overall control.

[0005] Although traditional voltage and reactive power control theories and technologies are relatively mature, they are limited by factors such as the overall system topology and communication. Currently applied reactive power control methods only consider the current time segment of the power system. The control logic is only triggered when the measured voltage value of the actual system exceeds the threshold (limit) or approaches the limit. This is actually a kind of lag control, which is essentially passive control with low accuracy and slow response speed. Summary of the Invention

[0006] The purpose of exemplary embodiments of the present invention is to provide a reactive voltage control method and a reactive voltage control device that can quickly control reactive voltage.

[0007] According to one aspect of the present invention, a reactive voltage control method is provided, the reactive voltage control method comprising: calculating the system impedance assessment value of the grid connection point at the current moment based on the electrical information of the grid connection point; determining the current system impedance value based on the system impedance assessment value; determining the proportional coefficient and integral coefficient of the proportional-integral algorithm according to the current system impedance value; and performing reactive voltage control of the grid connection point using the proportional-integral algorithm based on the determined proportional coefficient and integral coefficient.

[0008] According to an embodiment of the present invention, in response to the absolute value of the deviation between the current voltage of the grid connection point and the voltage at the previous moment in the electrical information quantity exceeding a predetermined threshold, a system impedance assessment value can be calculated based on the current voltage of the grid connection point, the voltage at the previous moment, the current reactive power value, and the reactive power value at the previous moment in the electrical information quantity; in response to the absolute value of the deviation between the current voltage of the grid connection point and the voltage at the previous moment in the electrical information quantity not exceeding a predetermined threshold, the system impedance assessment value of the grid connection point at the previous moment can be determined as the system impedance assessment value of the grid connection point at the current moment.

[0009] According to an embodiment of the present invention, the step of determining the current system impedance value based on the system impedance assessment value may include: determining whether the system impedance assessment value is valid based on whether the deviation between the system impedance assessment value and the average system impedance is within a predetermined range.

[0010] According to an embodiment of the present invention, in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance being within a first deviation range, the current system impedance value can be determined to be the system impedance assessment value; in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance being outside the first deviation range, the current system impedance value can be determined to be the typical system impedance value.

[0011] According to an embodiment of the present invention, the step of determining the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the current system impedance value may include: comparing the current system impedance value with a typical system impedance value to determine whether it is necessary to adjust at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm.

[0012] According to an embodiment of the present invention, in response to the absolute value of the deviation between the current system impedance value and the typical system impedance value being within a second deviation range, it can be determined that the proportional coefficient and integral coefficient of the proportional-integral algorithm do not need to be adjusted; in response to the absolute value of the deviation between the current system impedance value and the typical system impedance value not being within the second deviation range, it can be determined that at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm needs to be adjusted.

[0013] According to an embodiment of the present invention, the step of adjusting at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm may include: calculating the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the current system impedance value, the typical system impedance value, the initial setting value of the integral coefficient, and the initial setting value of the proportional coefficient; comparing the calculated proportional coefficient with the proportional coefficient range, and comparing the calculated integral coefficient with the integral coefficient range; and determining the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the comparison results.

[0014] According to an embodiment of the present invention, in response to the calculated proportional coefficient being within the range of proportional coefficients and the calculated integral coefficient being within the range of integral coefficients, the proportional coefficient and integral coefficient of the proportional-integral algorithm can be determined to be the calculated proportional coefficient and integral coefficient; in response to the calculated proportional coefficient being outside the range of proportional coefficients or the calculated integral coefficient being outside the range of integral coefficients, the proportional coefficient and integral coefficient of the proportional-integral algorithm can be determined to be the proportional coefficient and integral coefficient determined at the previous moment, or the proportional coefficient of the proportional-integral algorithm can be determined to be the limit value of the range of proportional coefficients and the integral coefficient of the proportional-integral algorithm can be determined to be the limit value of the range of integral coefficients.

[0015] According to an embodiment of the present invention, the initial value of the integral coefficient and the initial set value of the proportional coefficient can be obtained by tuning the control parameters of the proportional-integral algorithm based on the typical system impedance value.

[0016] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores instructions or code that, when executed by a processor, implement the above-described reactive voltage control method.

[0017] According to another aspect of the present invention, a reactive voltage control device is provided, comprising: a calculation module configured to calculate a system impedance assessment value of the grid connection point at the current moment based on electrical information of the grid connection point; a system impedance determination module configured to determine a current system impedance value based on the system impedance assessment value; a coefficient determination module configured to determine the proportional coefficient and integral coefficient of a proportional-integral controller according to the current system impedance value; and a reactive voltage control module configured to perform reactive voltage control of the grid connection point using a proportional-integral controller based on the determined proportional coefficient and integral coefficient.

[0018] According to an embodiment of the present invention, the calculation module may be further configured to: calculate a system impedance assessment value based on the current voltage of the grid connection point, the previous voltage, the current reactive power value, and the previous reactive power value in response to the absolute value of the deviation between the current voltage of the grid connection point and the previous voltage in the electrical information quantity exceeding a predetermined threshold; and determine the system impedance assessment value of the grid connection point at the previous moment as the system impedance assessment value of the grid connection point at the current moment in response to the absolute value of the deviation between the current voltage of the grid connection point and the previous voltage in the electrical information quantity not exceeding a predetermined threshold.

[0019] According to an embodiment of the present invention, the system impedance determination module may be further configured to: determine the current system impedance value as the system impedance assessment value in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance being within a first deviation range; and determine the current system impedance value as a typical system impedance value in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance being outside the first deviation range.

[0020] According to an embodiment of the present invention, the coefficient determination module may be further configured to adjust the proportional coefficient or integral coefficient of the proportional-integral controller based on the following: calculating the proportional coefficient and integral coefficient of the proportional-integral controller based on the current system impedance value, the typical system impedance value, the initial setting value of the integral coefficient, and the initial setting value of the proportional coefficient; comparing the calculated proportional coefficient with the proportional coefficient range, and comparing the calculated integral coefficient with the integral coefficient range; and determining the proportional coefficient and integral coefficient of the proportional-integral controller based on the comparison result.

[0021] According to an embodiment of the present invention, a computing device is provided, the computing device comprising: a computer-readable storage medium and a processor, the computer-readable storage medium storing instructions or code that, when executed by the processor, implement the above-described reactive voltage control method.

[0022] Further aspects and / or advantages of the general concept of the invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the general concept of the invention. Attached Figure Description

[0023] The above and other objects and features of exemplary embodiments of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, which illustrate exemplary embodiments, wherein:

[0024] Figures 1 to 5 This is a flowchart illustrating a reactive voltage control method according to an embodiment of the present invention;

[0025] Figure 6 This is a block diagram illustrating a reactive voltage control device according to an embodiment of the present invention. Detailed Implementation

[0026] The present invention will now be described in detail with reference to embodiments thereof, examples of which are illustrated in the accompanying drawings, wherein the same reference numerals always indicate the same parts. The embodiments will be described below with reference to the accompanying drawings in order to explain the present invention.

[0027] According to an embodiment of the present invention, a fast PI control strategy is used to control the reactive voltage of the power supply system, and the overall control has the advantages of fast adjustment speed and high accuracy.

[0028] Furthermore, this invention takes into account the variability of system operation modes by introducing real-time system impedance values ​​to monitor changes in system strength online. Based on these impedance changes, the PI control parameters are corrected online in real time, ensuring high precision of overall control across the entire time dimension. It also offers the advantage of fast response speed. Simultaneously, it improves the applicability of the overall control algorithm and ensures the stability of system operation and control.

[0029] Furthermore, the present invention can compare the parameters measured or calculated at each stage with thresholds or threshold ranges, thereby ensuring the accuracy of the parameters calculated or determined in each step and the safety of system control.

[0030] The reactive voltage control method and apparatus according to embodiments of the present invention can be used to control the reactive voltage of new energy power stations such as wind farms, but are not limited thereto. Here, a new energy power station can be a wind farm or a photovoltaic power station, or a power station including wind turbine generators and / or photovoltaic power generation systems. Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0031] Figures 1 to 5 This is a flowchart illustrating a reactive voltage control method according to an embodiment of the present invention.

[0032] According to an embodiment of the present invention, the reactive voltage control method may include steps S110, S120, S130 and S140.

[0033] like Figure 1 As shown, in step S110, the system impedance assessment value of the grid connection point at the current moment is calculated based on the electrical information of the grid connection point.

[0034] As an example, electrical information may include voltage and reactive power values, such as voltage or reactive power values ​​detected at the grid connection point.

[0035] It can detect the current voltage V at the grid connection point. + and the voltage V at the previous moment - The reactive power value Q at the current moment + and the reactive power value Q at the previous moment - And it can be based on the voltage V at the current moment. + and the voltage V at the previous moment - The reactive power value Q at the current moment + and the reactive power value Q at the previous moment - Calculate the system impedance assessment value at the grid connection point.

[0036] For example, the system impedance assessment value X can be calculated using the following formula 1. s .

[0037]

[0038] Alternatively, the system impedance assessment value can also be calculated based on other electrical information quantities, and the system impedance assessment value X can be calculated. s The method is not limited to this formula 1.

[0039] like Figure 1As shown, in step S120, the current system impedance value is determined based on the system impedance assessment value.

[0040] As an example, the calculation method of the system impedance assessment value can also be determined based on the change of the grid connection point voltage. That is, the step S110 of calculating the system impedance assessment value of the grid connection point at the current moment based on the electrical information of the grid connection point can include: determining the calculation method of the system impedance assessment value based on the current grid connection point voltage in the electrical information.

[0041] like Figure 2 As shown, in step S1101, the voltage V at the current moment is determined. + The voltage V at the previous moment - The deviation Δ1 between them. The current moment and the previous moment can be in different control cycles.

[0042] As an example, the system impedance assessment value can be recalculated when the absolute value of the voltage change at the grid connection point, |Δ1|, exceeds a predetermined threshold. Alternatively, the system impedance assessment value can be maintained if the absolute value of the voltage change at the grid connection point, |Δ1|, does not exceed the predetermined threshold. That is, the system impedance assessment value at the current moment is the same as the system impedance assessment value at the previous moment.

[0043] Specifically, such as Figure 2 As shown, in step S1102, the voltage V at the current moment is determined. + The voltage V at the previous moment - Does the absolute value of the deviation Δ1 between them, |Δ1|, exceed the predetermined threshold δ1?

[0044] In step S1104, if the absolute value of the deviation Δ1 does not exceed the predetermined threshold (|Δ1|≤δ1), the system impedance assessment value is maintained.

[0045] In step S1103, if the absolute value of the deviation Δ1, |Δ1|, exceeds a predetermined threshold (|Δ1|>δ1), then the system impedance assessment value X is calculated based on the electrical information quantity. s .

[0046] In other words, it can respond to the current voltage V at the grid connection point in the electrical information quantity. + Compared with the voltage V at the previous moment - The absolute value of the deviation between them exceeds a predetermined threshold, based on the current voltage V at the grid connection point in the electrical information quantity. + The voltage V at the previous moment - Current reactive power value Q + The reactive power value Q at the previous moment - Calculate the system impedance assessment value. The specific calculation method can be as shown in Equation 1 above, but is not limited to this.

[0047] It can respond to the current voltage V at the grid connection point in the electrical information quantity.+ Compared with the voltage V at the previous moment - If the absolute value of the deviation between the two does not exceed a predetermined threshold, the system impedance assessment value of the grid connection point at the previous moment is determined as the system impedance assessment value of the grid connection point at the current moment.

[0048] Furthermore, to avoid significant errors in system impedance calculations due to system fluctuations, the currently calculated system impedance assessment value can be X... s The system impedance is compared with the average system impedance to determine whether the system impedance assessment can be used as the current system impedance value.

[0049] As an example, step S120 of determining the current system impedance value based on the system impedance assessment value may include: determining whether the system impedance assessment value is valid based on whether the deviation between the system impedance assessment value and the average system impedance is within a predetermined range.

[0050] like Figure 3 As shown, in step S1201, the difference Δ2 or its absolute value |Δ2| between the system impedance assessment value and the average system impedance can be determined.

[0051] In step S1202, it can be determined whether the absolute value of the difference Δ2 between the system impedance assessment value and the average value of the system impedance, |Δ2|, is within the predetermined deviation range [X1,X2].

[0052] In step S1203, when the absolute value of the deviation between the system impedance assessment value and the average system impedance, |Δ2|, is within the first deviation range (i.e., X1≤|Δ2|≤X2), the current system impedance value X is determined. p The system impedance assessment value X s (that is, X) p =X s ).

[0053] In step S1204, when the absolute value of the deviation |Δ2| between the system impedance assessment value and the average system impedance is not within the first deviation range (i.e., X1 > |Δ2|, or |Δ2| > X2), the current system impedance value X is determined. p The typical system impedance value X t (that is, X) p =X t ).

[0054] In other words, the system impedance value is determined to be the system impedance assessment value in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance value being within a first deviation range.

[0055] In response to the deviation between the system impedance assessment value and the average system impedance being outside the first deviation range, the current system impedance value is determined to be a typical system impedance value.

[0056] In other words, when the system impedance assessment value is too large or too small, the system impedance assessment value is invalid and should not be used to determine the PI parameters (i.e., PI control parameters).

[0057] Valid system impedance assessment values ​​can be stored in the system impedance history data buffer for use when calculating new system impedance assessment values. The size of the system impedance buffer is set by a fixed value N, and the value of N is not less than 10.

[0058] If the absolute value of the deviation between the calculated system impedance assessment and the average system impedance exceeds a predetermined deviation range, it indicates that the system impedance assessment is invalid. In this case, the system impedance assessment or the current system impedance value should be equal to the average system impedance. The predetermined deviation range [X1, X2] is system-dependent; in engineering applications, an empirical value of 10Ω can be used. The average system impedance can be calculated based on historical system impedance assessments or the sum of system impedance values ​​divided by N.

[0059] like Figure 1 As shown, in step S130, the proportional coefficient and integral coefficient (i.e., PI control parameters) of the proportional-integral algorithm are determined based on the current system impedance value.

[0060] Specifically, step S130, which determines the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the current system impedance value, may include: comparing the current system impedance value with a typical system impedance value to determine whether at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm needs to be adjusted.

[0061] When the absolute value of the deviation between the current system impedance value and the typical system impedance value is greater than the preset threshold, it indicates that the system operation mode has changed and the PI control parameters need to be adjusted.

[0062] like Figure 4 As shown, the current system impedance value X can be determined in step S1301. p With typical system impedance value X t The absolute value of the deviation |Δ3|, (|Δ3|=X p -X t ).

[0063] In step S1302, it is determined whether the absolute value of the deviation between the current system impedance value and the typical system impedance value, |Δ3|, is within a predetermined deviation range (e.g., the second deviation range [X3,X4]).

[0064] If the absolute value of the deviation between the current system impedance value and the typical system impedance value, |Δ3|, is not within the predetermined deviation range, it can be determined in step S1303 that the PI parameter needs to be adjusted.

[0065] If the absolute value of the deviation between the current system impedance value and the typical system impedance value, |Δ3|, is within a predetermined deviation range, it can be determined in step S1304 that no adjustment of the PI parameter is required.

[0066] In other words, in response to the absolute value of the deviation between the current system impedance value and the typical system impedance value being within the second deviation range, the proportional coefficient and integral coefficient of the proportional-integral algorithm are determined without needing to be adjusted.

[0067] In response to the absolute value of the deviation between the current system impedance value and the typical system impedance value not being within the second deviation range, it is determined that at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm needs to be adjusted.

[0068] As an example, when the current system impedance value is greater than the typical system impedance value, it indicates that the system strength has weakened. At this time, the influence of the power station on the system becomes greater. Therefore, the PI control parameters (e.g., PI control parameter settings) can be reduced to avoid reactive power oscillations during the adjustment process.

[0069] When the current system impedance is less than the typical system impedance, it indicates that the system strength has increased. At this time, the influence of the station on the system is reduced. Therefore, the PI control parameters can be increased (for example, the PI parameter setting value can be increased to maintain the response speed of PI regulation).

[0070] As an example, such as Figure 5 As shown, the step of adjusting at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm may include: S13031, calculating the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the current system impedance value, the typical system impedance value, the initial setting value of the integral coefficient, and the initial setting value of the proportional coefficient; S13032, comparing the calculated proportional coefficient with the proportional coefficient range, and comparing the calculated integral coefficient with the integral coefficient range; S13033 and S13034, determining the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the comparison results.

[0071] For example, the PI parameter (PI control parameter) can be adjusted according to the following formula (2) and formula (3):

[0072] Kp=Kp_ini / (1+(Xs–Xs_ini) / Xs_ini) (2)

[0073] Ki=Ki_ini / (1+(Xs–Xs_ini) / Xs_ini) (3)

[0074] Where Kp is the actual proportional coefficient (i.e., proportional time constant) determined in the current control cycle, Ki is the actual integral coefficient (i.e., integral time constant) determined in the current control cycle, Kp_ini is the initial setting value of the proportional constant, Ki_ini is the initial setting value of the integral time constant, Xs is the current system impedance value in ohms, and Xs_ini is the typical system impedance value in ohms.

[0075] It should be noted that the Kp and Ki parameter correction algorithms given here are merely examples; other similar methods or schemes based on system and PI control parameter correction are within the scope of this invention. Each initial setpoint can be determined through simulation. Furthermore, the initial values ​​of the integral coefficient and the initial setpoint of the proportional coefficient can be obtained by tuning the control parameters of the proportional-integral algorithm based on typical system impedance values.

[0076] like Figure 5 As shown, in step S13033, in response to the calculated proportional coefficient being within the proportional coefficient range and the calculated integral coefficient being within the integral coefficient range, the proportional coefficient and integral coefficient of the proportional-integral algorithm are determined to be the calculated proportional coefficient and integral coefficient, that is, Kp and Ki determined by the above formula are determined as the PI control parameters for the current control cycle.

[0077] In step S13034, in response to the calculated proportional coefficient not being within the range of proportional coefficients or the calculated integral coefficient not being within the range of integral coefficients, the proportional coefficient and integral coefficient of the proportional-integral algorithm are determined to be the proportional coefficient and integral coefficient determined at the previous moment, or the proportional coefficient of the proportional-integral algorithm is determined to be the limit value of the range of proportional coefficients and the integral coefficient of the proportional-integral algorithm is determined to be the limit value of the range of integral coefficients. That is, the PI control parameters at the current moment or the current control cycle are maintained as the PI control parameters at the previous moment or the previous control cycle.

[0078] As an example, when it is determined that the PI control parameters need to be adjusted, both the proportional coefficient and the integral coefficient can be adjusted at the same time. However, this is just an example; it is possible to adjust only one of the two parameters.

[0079] As an example, if the calculated proportional coefficient is not within the range of proportional coefficients or the calculated integral coefficient is not within the range of integral coefficients, the proportional coefficient of the proportional-integral algorithm can be determined as the limit value (e.g., upper limit value) of the range of proportional coefficients, and / or the integral coefficient of the proportional-integral algorithm can be determined as the limit value (e.g., upper limit value) of the range of integral coefficients.

[0080] After determining the PI control parameters, reactive power control can be performed using these parameters, for example, such as... Figure 1 As shown, in step S140, reactive voltage control at the grid connection point is performed using a proportional-integral algorithm based on determined proportional and integral coefficients.

[0081] Specifically, the steps of using a proportional-integral algorithm based on a determined proportional coefficient and integral coefficient to control the reactive voltage at the grid connection point may include: using the deviation between the target reactive voltage value and the actual reactive voltage as the input of the proportional-integral algorithm, calculating the control command for the reactive power source of the new energy power station, and issuing the control command to the reactive power source so that the reactive voltage approaches the target reactive voltage value.

[0082] Here, using the deviation between the target reactive voltage value and the actual reactive voltage as the input to the proportional-integral algorithm is just an example. The deviation between reactive power and the actual reactive power can also be used as the input to the proportional-integral algorithm, or multiple variables can be controlled together.

[0083] It should be noted that the PI algorithm or PI controller of the present invention can also be regarded as a PID algorithm or PID controller, wherein the derivative coefficient is zero.

[0084] The reactive voltage control method and apparatus according to embodiments of the present invention can perform reactive voltage control based on system impedance, thereby adjusting PI control parameters in real time and improving the control accuracy and adjustment speed of reactive voltage.

[0085] Current reactive power control often employs fixed control methods, meaning that the system control setpoints cannot be adjusted in real time according to changes in the system's operating mode. This results in the reactive power control system, which uses fixed values, failing to detect system changes in a timely manner. Consequently, the reactive power control at the power plant performs well in the current time frame, but once the system operating mode changes, the overall control effect becomes less ideal. More seriously, the greater the change in system operating mode, the worse the overall control effect. Since changes in system operating mode are extremely common, this poses a significant challenge to meeting control requirements across the entire time dimension. Consequently, reactive power control fails to achieve the expected results in both the control process and objectives, ultimately failing to fundamentally improve the pass rate of reactive power control.

[0086] The reactive voltage control method according to embodiments of the present invention can adjust PI control parameters online in real time, and its control rate, control accuracy, and control effect are all superior to the current reactive voltage control strategy using a sampling fixed control method. The following will combine... Figure 6 A reactive voltage control method according to an embodiment of the present invention is described.

[0087] Figure 6 This is a block diagram illustrating a reactive voltage control device according to an embodiment of the present invention.

[0088] According to an embodiment of the present invention, the reactive voltage control device 400 may include a calculation module 410, a system impedance determination module 420, a coefficient determination module 430, and a reactive voltage control module 440.

[0089] The calculation module 410 can calculate the system impedance assessment value of the grid connection point at the current moment based on the electrical information of the grid connection point.

[0090] For example, the calculation module 410 can calculate based on the voltage V at the current moment. + and the voltage V at the previous moment - The reactive power value Q at the current moment + and the reactive power value Q at the previous moment - Calculate the system impedance assessment value at the grid connection point.

[0091] For example, the system impedance assessment value X can be calculated using Equation 1 above. s The system impedance assessment value can also be calculated using other electrical information, specifically the system impedance assessment value X. s The method is not limited to this formula 1.

[0092] The system impedance determination module 420 can determine the current system impedance value based on the system impedance assessment value.

[0093] The system impedance determination module 420 can determine the calculation method of the system impedance assessment value based on the current grid connection point voltage in the electrical information quantity.

[0094] As an example, the system impedance determination module 420 can determine the voltage V at the current moment. + The voltage V at the previous moment - Does the absolute value of the deviation Δ1 between them exceed the predetermined threshold δ1?

[0095] The system impedance determination module 420 can respond to the current voltage V at the grid connection point in the electrical information quantity. + Compared with the voltage V at the previous moment - The absolute value of the deviation between them exceeds a predetermined threshold, based on the current voltage V at the grid connection point in the electrical information quantity. + The voltage V at the previous moment - Current reactive power value Q + The reactive power value Q at the previous moment - Calculate the system impedance assessment value. The specific calculation method is shown in Equation 1 above.

[0096] The system impedance determination module 420 can respond to the current voltage V at the grid connection point in the electrical information quantity. + Compared with the voltage V at the previous moment -If the absolute value of the deviation between the two does not exceed a predetermined threshold, the system impedance assessment value of the grid connection point at the previous moment is determined as the system impedance assessment value of the grid connection point at the current moment.

[0097] Furthermore, to avoid significant errors in system impedance calculation due to system fluctuations, the system impedance determination module 420 can convert the currently calculated system impedance assessment value X... s The system impedance is compared with the average system impedance to determine whether the system impedance assessment can be used as the current system impedance value.

[0098] As an example, the system impedance determination module 420 can determine whether the system impedance assessment value is valid based on whether the deviation between the system impedance assessment value and the average system impedance is within a predetermined range.

[0099] For example, the system impedance determination module 420 can determine the absolute value |Δ2| of the difference Δ2 between the system impedance assessment value and the average value of the system impedance, and can determine whether the absolute value |Δ2| of the difference Δ2 between the system impedance assessment value and the average value of the system impedance is within the predetermined deviation range [X1,X2].

[0100] The system impedance determination module 420 can determine the system impedance value as the system impedance assessment value (i.e., X1≤|Δ2|≤X2) in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance within a first deviation range (i.e., X1≤|Δ2|≤X2). p =X s ).

[0101] The system impedance determination module 420 can determine the current system impedance value as a typical system impedance value (i.e., X1 > |Δ2|, or |Δ2| > X2) in response to the deviation between the system impedance assessment value and the average system impedance being outside a first deviation range (i.e., X1 > |Δ2|, or |Δ2| > X2). p =X t ).

[0102] In other words, when the system impedance assessment value is too large or too small, the system impedance determination module 420 determines the system impedance assessment value invalidally and it is not suitable for subsequent determination of PI parameters (i.e., PI control parameters).

[0103] The coefficient determination module 430 can determine the proportional coefficient and integral coefficient (i.e., PI control parameters) of the proportional-integral controller based on the current system impedance value.

[0104] As an example, the coefficient determination module 430 can determine the absolute value of the deviation between the current system impedance value and the typical system impedance value, |Δ3|, (|Δ3|=Xp-Xt), and can determine whether the absolute value of the deviation between the current system impedance value and the typical system impedance value, |Δ3|, is within a predetermined deviation range (e.g., a second deviation range [X3,X4]).

[0105] The coefficient determination module 430 can determine the proportional and integral coefficients of the proportional-integral controller without adjustment in response to the absolute value of the deviation between the current system impedance value and the typical system impedance value within a second deviation range.

[0106] The coefficient determination module 430 can determine at least one of the proportional coefficient and integral coefficient of the proportional-integral controller that needs to be adjusted if the absolute value of the deviation between the current system impedance value and the typical system impedance value is not within the second deviation range.

[0107] Specifically, when the current system impedance value is greater than the typical system impedance value, it indicates that the system strength has weakened. At this time, the influence of the power station on the system becomes greater. Therefore, the PI control parameters (e.g., PI control parameter settings) can be reduced to avoid reactive power oscillations during the adjustment process.

[0108] The coefficient determination module 430 can adjust the proportional coefficient or integral coefficient of the proportional-integral controller.

[0109] As an example, the coefficient determination module 430 can calculate the proportional coefficient and integral coefficient of the proportional-integral controller based on the current system impedance value, the typical system impedance value, the initial setting value of the integral coefficient, and the initial setting value of the proportional coefficient. It can compare the calculated proportional coefficient with the proportional coefficient range and the calculated integral coefficient with the integral coefficient range, and then determine the proportional coefficient and integral coefficient of the proportional-integral controller based on the comparison results.

[0110] Specifically, the coefficient determination module 430 can determine the proportional coefficient and integral coefficient of the proportional-integral controller based on the above equations (2) and (3). Further details will not be provided here.

[0111] The reactive voltage control module 440 can perform reactive voltage control at the grid connection point using a proportional-integral controller based on determined proportional and integral coefficients. The proportional-integral controller can be part of the reactive voltage control module 440.

[0112] Specifically, the reactive voltage control module 440 can use the deviation between the target reactive voltage value and the actual reactive voltage as input to the proportional-integral controller to calculate the control command for the reactive power source of the new energy power station, and issue the control command to the reactive power source to make the reactive voltage approach the target reactive voltage value. The reactive voltage control module 440 can not only use the deviation as input, but also directly use the detected reactive voltage, reactive power, etc., and can combine multiple parameters and multiple PI controllers for control.

[0113] Each of the above steps can be programmed as a software program or instruction. Therefore, the feedforward control method according to an exemplary embodiment of the present invention can be implemented via software. The computer-readable storage medium of the exemplary embodiment of the present invention can store a computer program, which, when executed by a processor, implements the reactive voltage control method as described in the above exemplary embodiment.

[0114] According to various embodiments of this disclosure, apparatus (e.g., modules or their functions) or methods can be implemented by programs or instructions stored in a computer-readable storage medium. When such instructions are executed by a processor, the processor can perform a function corresponding to the instruction or perform a method corresponding to the instruction. At least a portion of a module can be implemented (e.g., executed) by a processor. At least a portion of a programmed module can include modules, programs, routines, instruction sets, and procedures for performing at least one function. In one example, the instructions or software include machine code (such as machine code generated by a compiler) that is directly executed by one or more processors or computers. In another example, the instructions or software include higher-level code that is executed by one or more processors or computers using an interpreter. Instructions or software can be written using any programming language based on the block diagrams and flowcharts shown in the accompanying drawings and the corresponding description in the specification.

[0115] Computer-readable storage media include magnetic media such as floppy disks and magnetic tapes, optical media (including optical disc (CD) ROMs and DVD ROMs), magneto-optical media such as flexible optical discs, hardware devices such as ROMs and RAMs designed for storing and executing program commands, and flash memory. The program commands include language code executable by a computer using an interpreter and machine language code generated by a compiler. The aforementioned hardware devices can be implemented by one or more software modules for performing the operations of the various embodiments of this disclosure.

[0116] The modules or programming modules disclosed herein may include at least one of the aforementioned components, with some components omitted or others added. The operations of the modules, programming modules, or other components may be executed sequentially, in parallel, cyclically, or probingly. Furthermore, some operations may be executed in a different order, may be omitted, or may be extended with other operations.

[0117] The computer-readable storage medium and / or reactive voltage control device of exemplary embodiments of the present invention may be part of a computing device, controller, or control system.

[0118] For example, according to an exemplary embodiment of the present invention, a computing device may be provided, which may include: a processor (not shown) and a memory (not shown, which may be a computer-readable storage medium), wherein the memory stores a computer program (code or instructions) that, when executed by the processor, implements the reactive voltage control method as described in the exemplary embodiment above.

[0119] The reactive voltage control method and reactive voltage control device according to embodiments of the present invention can adjust PI control parameters online in real time, thereby improving the control rate and control accuracy of reactive voltage control.

[0120] While some exemplary embodiments of the invention have been shown and described, those skilled in the art will understand that modifications can be made to these embodiments without departing from the principles and spirit of the invention as defined by the claims and their equivalents. For example, technical features of different embodiments can be combined.

Claims

1. A reactive power voltage control method, characterized in that, include: The system impedance assessment value of the grid connection point at the current moment is calculated based on the electrical information of the grid connection point. The current system impedance value is determined based on the system impedance assessment value; Determine the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the current system impedance value; The reactive voltage control at the grid connection point is performed using a proportional-integral algorithm based on determined proportional and integral coefficients. The step of determining the current system impedance value based on the system impedance assessment value includes: in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance being within a first deviation range, determining the current system impedance value as the system impedance assessment value; If the absolute value of the deviation between the system impedance assessment value and the average system impedance is not within a first deviation range, the current system impedance value is determined to be a typical system impedance value. In response to the absolute value of the deviation between the current voltage and the previous voltage of the grid connection point in the electrical information quantity exceeding a predetermined threshold, the system impedance assessment value is calculated based on the current voltage, the previous voltage, the current reactive power value, and the previous reactive power value of the grid connection point in the electrical information quantity. In response to the absolute value of the deviation between the current voltage and the previous voltage at the grid connection point in the electrical information quantity not exceeding a predetermined threshold, the system impedance assessment value of the grid connection point at the previous moment is determined as the system impedance assessment value of the grid connection point at the current moment. The step of determining the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the current system impedance value includes: comparing the current system impedance value with a typical system impedance value to determine whether it is necessary to adjust at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm. In response to the absolute value of the deviation between the current system impedance value and the typical system impedance value being within the second deviation range, the proportional coefficient and integral coefficient of the proportional-integral algorithm that do not need to be adjusted are determined. In response to the absolute value of the deviation between the current system impedance value and the typical system impedance value not being within the second deviation range, determining that at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm needs to be adjusted, the steps of adjusting at least one of the proportional coefficient and integral coefficient of the proportional-integral algorithm include: Calculate the proportional coefficient and integral coefficient of the proportional-integral algorithm based on the current system impedance value, the typical system impedance value, the initial setting value of the integral coefficient, and the initial setting value of the proportional coefficient. Compare the calculated proportionality coefficient with the range of proportionality coefficients, and compare the calculated integral coefficient with the range of integral coefficients; Based on the comparison results, the proportional coefficient and integral coefficient of the proportional-integral algorithm are determined. In response to the calculated proportional coefficient being within the range of proportional coefficients and the calculated integral coefficient being within the range of integral coefficients, the proportional coefficient and integral coefficient of the proportional-integral algorithm are determined as the calculated proportional coefficient and integral coefficient. In response to the calculated proportional coefficient being outside the range of proportional coefficients or the calculated integral coefficient being outside the range of integral coefficients, the proportional coefficients and integral coefficients of the proportional-integral algorithm are determined to be those determined at the previous moment.

2. The reactive voltage control method according to claim 1, characterized in that, The initial values ​​of the integral coefficient and the initial set value of the proportional-integral (PI) coefficient are obtained by tuning the control parameters of the PI algorithm based on the typical system impedance value.

3. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions or code that, when executed by a processor, implement the reactive voltage control method according to any one of claims 1 to 2.

4. A reactive power voltage control device, characterized in that, include: The calculation module is configured to calculate the system impedance assessment value of the grid connection point at the current moment based on the electrical information of the grid connection point; The system impedance determination module is configured to determine the current system impedance value based on the system impedance assessment value; The coefficient determination module is configured to determine the proportional coefficient and integral coefficient of the proportional-integral controller based on the current system impedance value. The reactive voltage control module is configured to perform reactive voltage control at the grid connection point using a proportional-integral controller based on determined proportional and integral coefficients. The system impedance determination module is further configured to: determine the current system impedance value as the system impedance assessment value in response to the absolute value of the deviation between the system impedance assessment value and the average system impedance being within a first deviation range; In response to the absolute value of the deviation between the system impedance assessment value and the average system impedance being outside a first deviation range, the current system impedance value is determined to be a typical system impedance value. The calculation module is further configured to: in response to the absolute value of the deviation between the current voltage of the grid connection point and the voltage at the previous moment in the electrical information quantity exceeding a predetermined threshold, calculate the system impedance assessment value based on the current voltage of the grid connection point, the voltage at the previous moment, the current reactive power value, and the reactive power value at the previous moment in the electrical information quantity. In response to the absolute value of the deviation between the current voltage and the previous voltage at the grid connection point in the electrical information quantity not exceeding a predetermined threshold, the system impedance assessment value of the grid connection point at the previous moment is determined as the system impedance assessment value of the grid connection point at the current moment. The coefficient determination module is further configured to adjust the proportional or integral coefficient of the proportional-integral controller based on the following method: Calculate the proportional and integral coefficients of the proportional-integral controller based on the current system impedance value, the typical system impedance value, the initial setting value of the integral coefficient, and the initial setting value of the proportional coefficient. Compare the calculated proportionality coefficient with the range of proportionality coefficients, and compare the calculated integral coefficient with the range of integral coefficients; Based on the comparison results, the proportional and integral coefficients of the proportional-integral controller are determined. The coefficient determination module is further configured to: in response to the calculated proportional coefficient being within the range of proportional coefficients and the calculated integral coefficient being within the range of integral coefficients, determine the proportional coefficient and integral coefficient of the proportional-integral algorithm as the calculated proportional coefficient and integral coefficient. In response to the calculated proportional coefficient being outside the range of proportional coefficients or the calculated integral coefficient being outside the range of integral coefficients, the proportional coefficients and integral coefficients of the proportional-integral algorithm are determined to be those determined at the previous moment.

5. A computing device, characterized in that... include: A computer-readable storage medium and a processor, the computer-readable storage medium storing instructions or code that, when executed by the processor, implement the reactive voltage control method according to any one of claims 1 to 2.

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